Hello Again,

I have another project comprised of a 16 push-button membrane keypad.
I am using a 18F2420, which is a pretty vanilla 18F PIC with enough
I/O and a UART and I2C. I simply need to detect a button press and
send it over both the UART and I2C.

I have some questions/seeking advice.

I might stick 8 buttons on Port A and 8 buttons on Port B. Pull down
each Normally Open button to ground, and a button press will pull the
line high.

I've never interfaced anything to the PGD/PGC lines, should I put a
10K (100K?) resistor in series with the pin, then go to the
pulldown/switch (see:
http://img.photobucket.com/albums/v55/goldscott/pgd-pgc-question.png)?

What are some ways to go about this while keeping power low? I know I
can poll each button until I find one high, but the processor will
always be at full power doing this. What about using a simple logic
gate to OR/NOR all the switches together to an interrupt pin to wake
the processor up?

What other suggestions do you have, and what issues might I run into?

Thanks,
Scott Larson
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